1. Field of the Invention
The invention is in the field of nucleonic radiation responsive measuring and detecting systems.
2. Prior Art
As is known, there are various types of instruments which are used to detect the presence, position and/or distance of a target body from a monitoring body. As used herein, the monitoring body is defined as that body which carries the detecting instrumentation. Typical examples of conventional type instruments are those which are barometric pressure, radar and radio waves to detect the target body. As explained in U.S. Pat. No. 3,508,046, issued Apr. 21, 1970 to Anton et al., instruments which make use of the above-listed phenomenons suffer serious disadvantages when the instruments are used to measure the distance between the target and monitoring bodies under certain conditions, especially where small distances are being measured.
As further explained in the Anton et al. patent, several of the problems with the above-listed types of range measuring instruments have been alleviated with the advent of a new type of range measuring apparatus which makes use of nucleonic radiation. In such range measuring devices, the monitoring body is fitted with a source of nucleonic radiation. Typical sources include those which produce alpha, beta, gamma or X-radiation. Conventionally, the source radiation is collimated, using a suitable radiation lens system, to thereby direct the radiation to a defined area on the target body. A portion of the transmitted radiation is reflected or back scattered from the target body surface and returned to the monitoring body where suitable detectors to produce an electrical signal proportional to the reflected radiation over a given time interval.
In accordance with the Anton et al teaching, the distance between the target and monitoring objects can be determined using a two detector system. The specifics of the distance measuring technique are set out in detail therein and need not be described herein.
A similar type distance measuring device, dependent upon reflected radiation from the target body, is described in U.S. Pat. No. 3,483,371 issued Dec. 9, 1969 to Canup et al. As with the Anton et al patent, radiation reflected from the target body and originating at the monitoring body, is detected and used for range measuring purposes.
Radiation responsive instruments have also been used to determine the orientation of a moving body in the atmosphere. Such an instrument is described in U.S. Pat. No. 3,557,366 issued Jan. 19, 1971 to Jernigan, Jr. Again, the detector is specifically responsive to radiation produced by the monitoring body and reflected from the target.
It is also known to use nucleonic radiation deflected from the surface of a terrestrial body for the purposes of terrestrial prospecting and terrain mapping. Examples of such techniques are described in U.S. Pat. No. 3,341,706 issued Sept. 12, 1967 to Swift et al. and U.S. Pat. No. Re. 26,335 issued Jan. 9, 1968 to Chope.
A problem with such radiation responsive instruments, whether they be used for object locating purposes or terrain analysis, is that they are susceptible to interference from extraneous radiation and particularly from reflected radiation emanating from non-target objects. To overcome this problem, vaarious additional sophisticated and expensive equipment has been utilized to counteract the unwanted reflections. For example, as indicated in the Anton et al patent, an extra detector and associated circuitry may be used in an attempt to alleviate the problem associated with extraneous reflections. The present invention solves the problem of unwanted reflections and extraneous radiation received by the detector without the need of additional sophisticated and expensive equipment.